Right-click on a file, and this script will decide what conversions are appropriate, ask some questions about what you want, and execute the proper command and options to convert it into something else.

There's a lot of description here, but you don't need any of it to make this work.
Just download and extract. Then do one or more of these with the file "avconvert":
(1) move (or copy or link) it to ~/.gnome2/nautilus-scripts
(2) move (or copy or link) it to somewhere in $PATH (eg /usr/local/bin)
..(obviously don't move it twice :-)
(3) do #2, then add it as a nautilus-action (The Command "Parameters" must be "space-separated list of selected filenames", and "Working Directory" must be "first base directory". On Fedora, these are %F and %d)
(4) add it to Gnome panel/launch-bar (drag/drop or right-click panel Add/Custom-Application)

...Depending on 1, 2, 3, and 4 above (you can do any combination of these), you can now:
(1) right-click on selected icon(s) and choose the script
(2) from command line: avconvert filename (quote name(s) with spaces, multiple files OK)
(3) right-click on selected icon(s) and choose "Avconvert"
(4) click the icon to launch -or- drag-and-drop file(s) on the icon

To repeat, you can do as many of these as you want. For example: move the file to ~/.gnome2/natuilus-scripts, then link that to /usr/local/bin, then add it as a nautilus-action, then add it to the gnome-panel.

Much more than a quick shortcut to a common command, this shell script is over 2000 lines of code!

If you feel inclined not to vote "good", tell me why - I'm still actively developing this.
If you like it and you're not registered, take the time to sign up and vote....
After all, I took the time to write this and give it away! :-) :-)

If this has become a tool you use regularly, PLEASE consider a small donation
A lot of time and effort has gone into bringing this to the "free" world

The first run will create some files in ~/.config/avconvert. The files "avconvert", "avconvert.lang", and "avconvert.ffopts.custom" may be hand-edited. A default file will be recreated if any file is missing.

When using Key-In-Options during audio or video conversion, your ffmpeg options can be saved into the menu for future use. When your Key-In options end in a comment (as in "# my conversion"), a line will be automatically added to the 'custom' section of the ffmpeg options menu.

There's a progress indicator during conversions. In most cases, it estimates that the result file will grow to the size of the source file. This is not always the case because depending on the conversion the result may be larger or smaller than the original, so it may only reach 25-30% and be finished or quickly rise to 98% and hover there depending on your conversion. Be patient - behind the scenes, the progress window stays up as long as the result file is growing.

AUDIO: Converts between various formats (see below).

VIDEO: Converts between various formats. Can also produce audio-only from a video source. Video size can be scaled by specifying a new width - the new height is calculated based on aspect ratio. A video can also be letter-boxed by choosing the aspect ratio of your display device - calculation automatically determines whether to pad on top/bottom or left/right. Videos can also be rotated to compensate for the type of recorder used (this feature is the only one that relies on mencoder). NOTE REGARDING ROTATION - mencoder has some codec limitations, and depending on the source or destination file type, rotation may fail. This will be detected and reported, but without automatically fixing it. The best course of action is to convert the source first, perhaps to AVI, then use THAT file as the source for your rotation and other changes.

AUDIO AND VIDEO: Can adjust audio volume, sample rate, bitrate. In fact, you can do anything ffmpeg is capable of. Options in default menus offer common operations, but a special KEY-IN function lets you test your own and store them in your own custom file. Further, there's a file of user-submitted options (downloaded separately).

VIDEO FRAMES: Converts an input video into a series of frames in either jpg or png format. The capture rate can range from 1 to 60 seconds between frames, or 'all'.

VIDEO MERGE: If you have selected multiple AVI video files, you'll be given the option of merging them. Other video formats will need to be converted to AVI first. Pre-converting is also recommended if AVI files of differing video or audio quality are to be merged. The final AVI can of course then be converted to the format of your choice.

IMAGES: Convert between various formats. Optionally set resolution for output. If outputting jpg, optionally set quality. A single conversion can specify multiple output types and multiple resolutions.

IMAGE SPECIAL CASES: Converting an animated gif to a format other than gif will produce a separate file for each frame in the source. Converting a pdf to an format other than pdf does the same thing. In both cases the "progress indicator" will suggest that there was an error, but this is only because the files created are not named in accordance with what it expects. Be patient if the source contains many frames, and do not click Cancel to the progress window. Also, conversion of a .psd (or similar) which contains layers will generate multiple images in some formats (eg jpg), or an animation (eg gif), so you may want to flatten them first.

TEXT to TEXT: Various conversions between TXT, RTF, HTML, M$Office and OpenOffice, with more being added.

TEXT to IMAGE: Produces an image of your .txt file. Choose the output image size, font size, colors, border, and font. Text is automatically rewrapped as needed, based on the requested image width and font size. After wrapping, if the text will not fit on a single image vertically, multiple image pages will be generated.

GENERAL:
- The source file is not overwritten. The destination file is named for the source with a new extension.
- An image conversion will also insert resolution into the destination name.
- If any conversion would produce the source filename (eg changing image jpg quality only, or audio bitrate only, or same conversion twice), "new" is inserted into destination name or user is prompted to supply a name.

If you are missing any packages or plug-ins that it relies on, it will try to help. Help and notes are within the script at the very bottom.

Upon startup, "ffmpeg" and "file" are both executed against the source file, and the information gathered is displayed in the initial windows. This is helpful in deciding what choices to make, especially if the source file happens to be of an 'unknown' type. If the script cannot figure out what to do with a file, it will let you specify whether to treat it as audio, video, image, or text.

The destination is chosen from a list of common and appropriate file extensions. If you want something that's not listed, you can click OTHER and type in any extension that is appropriate for the input file type and conversion being done.

For a typical system (eg, mine :-) conversions for the following image, audio and video formats...

[ READ ME!! ] After processing, the last part of the output from the actual conversion program used is displayed to confirm proper operation or to help diagnose any problems. If there are problems, you can view the complete output: in /tmp, list the files with "ls -lrt" which will show the newest at the bottom. The files that capture conversion output are named as follows: conversion-program.NNNNN where NNNNN is the PID of the process that ran. For example, you might see "ffmpeg.8512" or "antiword.405". Just view the file and look for the first error listed, which is probably the culprit.

=====

0.56 It is now possible to replace originals during a conversion IF:
1 - converting images
2 - converting into the source folder
3 - converting to only one file type
4 - converting to only one resolution
If these conditions are all true, you will be prompted before the conversion begins. If you choose YES:
1 - originals are replaced with the converted files
2 - the new files will have a different extension if appropriate
3 - the new file names will not have the resolution inserted

0.60 You are invited to submit your own custom option sets, which will be added to a "user submissions" config file that will be posted here and available for download!

0.61 Now recognizes .vob files - just mount your DVD and rip away!

0.65 When a keyed-in option is used in audio or video conversion, if you add a "comment" (a # followed by text), then that option set will be automatically added to your ~/.config/avconvert/avconvert.ffopts.custom file for future use

0.90 Merging multiple AVI files. If all the files you select are AVI, a new prompt will offer to merge them to a single AVI. All the source files should be of the same size/bitrate/etc (you may want to pre-convert them to ensure this).

0.93 New "veryquiet" option to completely turn off progress popups. To enable this after upgrading to 0.93, go to the directory ~/.config/avconvert and either remove the file "avconvert" (the next run will create a new one), or edit that file and add the line "veryquiet=y".

0.94 Translations work once again (if you have them turned off, just remove ~/.config/avconvert/avconvert.lang to reset). Various minor fixes as well, like an adjustment for a change in how Zenity works.

0.95 Google no longer offers the translation API as a free service. Changed things to use the built-in "libtranslate" function, which automatically references multiple such services. It's a little slower, but works.

0.97 Adjustments to detecting libtranslate. Also fixed a bug that, when converting multiple multimedia files, destination folder is asked for in each loop.

0.98 Recognizes when only VOB file(s) are selected and offers to rip DVD to an AVI on the Desktop.

0.99 Added SVG file type to image conversions. Due to a change in ffmpeg output when analyzing a video, rewrote the parsing of this output (still compatible with older ffmpeg versions).

To both your suggestions...

Regarding an integrity check, I may include this in the actual script, though it does take as long to run as to play the audio or video file. But for now, here is the command to run:
ffmpeg -v error -i filename.ext -f null -

Regarding tags, it appears that these can be specified directly in the command line. This means that it would be simple for you to add them using the "key in options" function that is already in my script. Further, this function in the script allows you to permanently add them to your menus simply by providing a comment when you key them in. Message me if you need more instruction than that.

This web page shows the options and how to specify them:
http://jonhall.info/how_to/create_id3_tags_using_ffmpeg